Site Logo Block causing division by zero notice when image dimensions are not available

[audrasjb]

Description

Please note that this is a report coming from Trac, and that maximus80 deserves the props here.

Copy-paste from Trac:

Notice is
Warning: Division by zero in wp-includes/blocks/site-logo.php on line 21

This will happen when the dimensions of the image used inside the site logo block can't be retrieved for some reason.

Example: SVG image being used. That will lead to the divisors being zero here: https://core.trac.wordpress.org/browser/branches/5.9/src/wp-includes/blocks/site-logo.php#L20

Easiest way to fix would be to replace line 17:
if ( empty( $attributes['width'] ) || empty( $image ) ) { with
if ( empty( $attributes['width'] ) || empty( $image ) || ! $image[1] || ! $image[2] ) {

Step-by-step reproduction instructions

1. Install a plugin to make sure you can upload SVGs to your website
2. Add a Site logo block
3. Use the SVGs
4. See the notice thrown by the block server-side rendering

Screenshots, screen recording, code snippet

No response

Environment info

• WordPress 5.9
• Random plugin to allow SVG uploads

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[maximus80]

Thanks for porting this over here @audrasjb 👍